Electronic communication systems frequently require contemporaneous transmission and reception of electromagnetic signals through a shared resource. For example, a mobile phone will both transmit and receive respective signals on the same antenna. An antenna is commonly shared with a transmitter and a receiver with a duplexer, which minimizes interference between the transmitter and receiver paths, by using bulky filters and antenna impedance matching circuitry (e.g. balancing networks).
In particular, Surface Acoustic Wave (SAW) and Bulk Acoustic Wave (BAW) filters are used in many cellular telephone duplexers adding to cost and space. Furthermore, the balancing network can consume up to 50% of the transmitter power as well as degrade the isolation between transmitter and receiver paths due to manufacturing and environmental variations in the components used to match the antenna impedance.